A novel BRET-based assay to investigate binding and residence times of unmodified ligands to the human lysosomal ion channel TRPML1 in intact cells

J Biol Chem. 2023 May 10;104807. doi: 10.1016/j.jbc.2023.104807. Online ahead of print.


Here we report a Bioluminescence Resonance Energy Transfer (BRET) assay as a novel way to investigate the binding of unlabeled ligands to the human Transient Receptor Potential Mucolipin 1 (hTRPML1), a lysosomal ion channel involved in several genetic diseases and cancer progression. This novel BRET assay can be used to determine equilibrium and kinetic binding parameters of unlabeled compounds to hTRPML1 using intact human-derived cells, thus complementing the information obtained using functional assays based on ion channel activation. We expect this new BRET assay to expedite the identification and optimization of cell-permeable ligands that interact with hTRPML1 within the physiologically-relevant environment of lysosomes.

Keywords: bioluminescence resonance energy transfer (BRET); calcium channel; lysosome; membrane protein; transient receptor potential channels (TRP channels).